The present invention relates to an ultrasonic probe device adapted for use in ultrasonic diagnosis and, more specifically, to an ultrasonic probe device which is capable of easily interposing a liquid acoustical medium between an ultrasonic transmitting/receiving face of a probe and the surface of a subject to be examined.
According to diagnostic techniques using ultrasonic probes, the movements of unborn babies, the defects or the internal organs of various portions of living bodies or organisms are observed as cross-sectional images by ultrasonic diagnoses. Generally, the surface of an organism is not even, but undulating. On the other hand, the ultrasonic transmitting/receiving face of a probe may be regarded as substantially even and rigid. Accordingly, it is hard to acoustically couple the probe and organism by bringing the ultrasonic transmitting/receiving face into contact with the organism's surface. Thus, in some cases, it is impossible to send ultrasonic waves into the organism to detect ultrasonic echoes therefrom.
Thus, a method has been proposed in which water, whose acoustical characteristics resemble that of the organism, is contained in a water bag made of, e.g., vinyl, with the water bag being interposed between the probe and the organism, so that the probe and the organism with an irregular surface shape are acoustically coupled by means of the water, which serves as an acoustical medium. In conventional ultrasonic diagnosis, however, a filled water bag, attached to a device under the probe, is placed on the regions of the human body to be examined, and the probe then performs the scanning operation. Not only is this device bulky, but the device for placing the water bag on the region to be examined is also large. Thus, the device is low in operating efficiency and requires a good deal of space.
In some ultrasonic probe devices, the water bag is attached directly to the probe. In these devices, however, the watertightness between the water bag and probe is not satisfactory, so that water is liable to leak, and operating efficiency is poor. Alternatively, the probe may be used singly, without being combined with the water bag. In the prior art ultrasonic probe device, however, it is not easy to attach and detach the water bag to and from the probe. Moreover, it is hard to pour water into the water bag or remove air bubbles therefrom. The probe and a living body may be coupled acoustically by interposing therebetween a filled, watertight rubber or vinyl bag. In this case, ultrasonic waves pass the rubber or vinyl sheet wall of the water bag twice. Therefore, the ultrasonic waves are greatly attenuated by the sheet wall.